function ControleVide1()
{
	var verim = 0;
	for (i=1; i<document.form_2.courriel.value.length -4; i++)
	{
		if ( document.form_2.courriel.value.charAt(i) == "@")
		{
			verim = 1;
		}
	}
	
	if (verim == 0)
	{
		alert('Le champ " COURRIEL " non valide !');
		document.form_2.courriel.focus();
	}

	else
	{
		document.form_2.method = "POST";
		document.form_2.action = "achat_redirect.php";
		document.form_2.submit();
	}
}